On the EMB 145 aircraft, thrust reversers are optional equipment. Trans States Airlines operates some EMB 145s without thrust reversers.
See below:
"Many of the ERJ-145s operating as United Express are the only ERJ-145s in the United States operating without thrust reversers in an effort to save weight and money. These aircraft were purchased from Swissair."From:
http://en.wikipedia.org/wiki/Trans_States_Airlines"This airplane will have a novel or unusual design feature associated with thrust reversers as optional equipment."From:
http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgSC.nsf/0/F90776A5B54BD41B86256BDE006FAFA3?OpenDocumentI was on a Delta Connection EMB 145 the other week and it defiantly had thrust reversers!
#1 is Delta Connection (Chautauqua Airlines) N273SK (cn 145331) with reversers deployed.
#2 is United Express (Trans States Airlines) N839HK (cn 14500829). Note the lack of reverser doors.
#3 is the best example: American Connection (Trans States Airlines) Embraer EMB-145LR (ERJ-145LR)N825HK. No reverser doors.
#4 is Trans States Airlines Embraer EMB-145ER (ERJ-145ER) N809HK. Some of Trans States Airlines' EMB 145s do have reversers. Doors are clearly visible in the all white scheme.